Organic light-emitting diode

ABSTRACT

An organic light-emitting diode includes a substrate; a first electrode on the substrate; a second electrode disposed opposite to the first electrode; an emission layer disposed between the first electrode and the second electrode; a hole migration region disposed between the first electrode and the emission layer; and an electron migration region disposed between the emission layer and the second electrode, wherein the hole migration region comprises a first compound represented by Formula 1 below, and at least one of the hole migration region and the emission layer comprises a second compound represented by Formula 2 below. Substituents in Formulae 1 and 2 are the same as described in the specification.

CLAIM OF PRIORITY

This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. § 119 from an application for ORGANIC LIGHT-EMITTING DIODE, earlier filed in the Korean Intellectual Property Office on Dec. 27, 2012 and there duly assigned Serial No. 10-2012-0155317.

BACKGROUND OF THE INVENTION Field of the Invention

One or more embodiments of the present invention relate to an organic light-emitting diode including a hole migration region.

Description of the Related Art

Organic light-emitting diodes (OLEDs), which are self-emitting diodes, have advantages such as wide viewing angles, excellent contrast, quick response, high brightness, excellent driving voltage characteristics, and can provide multicolored images.

A typical OLED has a structure including a substrate, and an anode, a hole transport layer (HTL), an second electrode (EML), an electron transport layer (ETL), and a cathode which are sequentially stacked on the substrate. In this regard, the HTL, the EML, and the ETL are organic thin films formed of organic compounds.

An operating principle of an OLED having the above-described structure is as follows.

When a voltage is applied between the anode and the cathode, holes injected from the anode move to the EML via the HTL, and electrons injected from the cathode move to the EML via the ETL. The holes and electrons recombine in the EML to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted.

SUMMARY OF THE INVENTION

One or more embodiments of the present invention include an organic light-emitting diode including a hole migration region which has a novel structure.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to one or more embodiments of the present invention, an organic light-emitting diode may include a substrate; a first electrode on the substrate; a second electrode disposed opposite to the first electrode; an emission layer disposed between the first electrode and the second electrode; a hole migration region disposed between the first electrode and the emission layer; and an electron migration region disposed between the emission layer and the second electrode, wherein the hole migration region may include a first compound represented by Formula 1 below, and at least one of the hole migration region and the emission layer may include a second compound represented by Formula 2 below:

wherein, in Formulae 1 and 2, Ar₁₀₁, Ar₁₀₂, Ar₁, and Ar₂ may be each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, and a substituted or unsubstituted C₂-C₆₀ heteroarylene group; xa, xb, a, and b may be each independently an integer from 0 to 5; R₁₀₁, R₁₀₉, R₁, and R₂ may be each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, and a substituted or unsubstituted C₂-C₆₀ heteroaryl group; R₁₀₂ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₁ to R₁₄ may be each independently selected from hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl group, —N(Q₁)(Q₂), and —Si(Q₃)(Q₄)(Q₅) (where Q₁ to Q₅ may be each independently a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a C₆-C₆₀ aryl group, or a C₂-C₆₀ heteroaryl group); c1 and c4 may be each independently an integer from 1 to 4; and c2 and c3 may be each independently an integer from 1 to 3.

The hole migration region of the organic light-emitting diode may include i) a first hole transport layer, and ii) a second hole transport layer disposed between the first hole transport layer and the emission layer; and the first compound may be in the first hole transport layer, and the second compound may be in the second hole transport layer.

The hole migration region of the organic light-emitting diode may include a hole transport layer, the first compound may be in the hole transport layer, and the second compound may be in the emission layer.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention, and many of the attendant advantages thereof, will be readily apparent as the present invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a schematic view of a structure of an organic light-emitting diode according to an embodiment of the present invention;

FIG. 2 is a schematic view of a structure of an organic light-emitting diode according to another embodiment of the present invention; and

FIG. 3 is a schematic view of a structure of an organic light-emitting diode according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

Referring to FIG. 1, an organic light emitting diode 10 according to an embodiment of the present invention may have a structure including a substrate 11, a first electrode 12, a hole migration region 13, an emission layer (EML) 15, an electron migration region 17, and a second electrode 19 that are sequentially stacked on one another.

The substrate 11 may be any substrate that is used in existing organic light-emitting diodes. In some embodiments the substrate 11 may be a glass substrate or a transparent plastic substrate with strong mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

The first electrode 12 may be formed by depositing or sputtering a first electrode-forming material on the substrate 11. When the first electrode 12 is an anode, a material having a high work function may be used as the first electrode-forming material to facilitate hole injection. The first electrode 12 may be a reflective electrode or a transmission electrode. Transparent and conductive materials such as ITO, IZO, SnO₂, and ZnO may be used to form the first electrode 12. The first electrode 12 may be formed as a reflective electrode using magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or the like.

The first electrode 12 may have a single-layer structure or a multi-layer structure including at least two layers. For example, the first electrode 12 may have a three-layered structure of ITO/Ag/ITO, but is not limited thereto.

The first electrode 12 may be a hole-injecting electrode (anode).

The second electrode 19 may be disposed opposite to the first electrode 12. The second electrode 19 may be a cathode, which is an electron injecting electrode. A metal for forming the second electrode 19 may be a metal, an alloy, an electrically conductive compound, which have a low-work function, or a mixture thereof. In this regard, the second electrode 19 may be formed of lithium (Li), magnesium (Mg), aluminum (Al), aluminum (Al)-lithium (Li), calcium (Ca), magnesium (Mg)-indium (In), magnesium (Mg)-silver (Ag), or the like, and may be formed as a thin film type transmission electrode. In some embodiments, to manufacture a top-emission light-emitting diode, the transmission electrode may be formed of indium tin oxide (ITO) or indium zinc oxide (IZO).

The EML 15 may be disposed between the first electrode 12 and the second electrode 19, the hole migration region 13 may be disposed between the first electrode 12 and the EML 15, and the electron migration region 17 may be disposed between the EML 15 and the second electrode 19.

In the organic light-emitting diode 10, holes are injected through the first electrode 12 to migrate to the EML 15 through the hole migration region 13, while electrons are injected through second electrode 19 to migrate to the EML 15 through the electron migration region 17. The holes and electrons recombine in the EML 15 to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted.

The hole migration region 13 may include a first compound represented by Formula 1 below, and at least one of the hole migration region 13 and the EML 15 may include a second compound represented by Formula 2 below.

In Formulae 1 and 2, Ar₁₀₁, Ar₁₀₂, Ar₁, and Ar₂ may be each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, and a substituted or unsubstituted C₂-C₆₀ heteroarylene group.

For example, in Formulae 1 and 2, Ar₁₀₁, Ar₁₀₂, Ar₁, and Ar₂ may be each independently a substituted or unsubstituted phenylene group, a substituted or unsubstituted pentalenylene group, a substituted or unsubstituted indenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted azulenylene group, a substituted or unsubstituted heptalenylene group, a substituted or unsubstituted indacenylene group, a substituted or unsubstituted acenaphthylene group, a substituted or unsubstituted fluorenylene group, a substituted or unsubstituted spiro-fluorenylene group, a substituted or unsubstituted phenalenylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted anthrylene group, a substituted or unsubstituted fluoranthenylene group, a substituted or unsubstituted triphenylenylene group, a substituted or unsubstituted pyrenylene group, a substituted or unsubstituted chrysenylene group, a substituted or unsubstituted naphthacenylene group, a substituted or unsubstituted picenylene group, a substituted or unsubstituted perylenylene group, a substituted or unsubstituted pentaphenylene group, a substituted or unsubstituted hexacenylene group, a substituted or unsubstituted pyrrolylene group, a substituted or unsubstituted imidazolylene group, a substituted or unsubstituted pyrazolylene group, a substituted or unsubstituted pyridinylene group, a substituted or unsubstituted pyrazinylene group, a substituted or unsubstituted pyrimidinylene group, a substituted or unsubstituted pyridazinylene group, a substituted or unsubstituted isoindolylene group, a substituted or unsubstituted indolylene group, a substituted or unsubstituted indazolylene group, a substituted or unsubstituted purinylene group, a substituted or unsubstituted quinolinylene group, a substituted or unsubstituted benzo quinolinylene group, a substituted or unsubstituted phthalazinylene group, a substituted or unsubstituted naphthyridinylene group, a substituted or unsubstituted quinoxalinylene group, a substituted or unsubstituted quinazolinylene group, a substituted or unsubstituted cinnolinylene group, a substituted or unsubstituted carbazolylene group, a substituted or unsubstituted phenanthridinylene group, a substituted or unsubstituted acridinylene group, a substituted or unsubstituted phenanthrolinylene group, a substituted or unsubstituted phenazinylene group, a substituted or unsubstituted benzooxazolylene group, a substituted or unsubstituted benzoimidazolylene group, a substituted or unsubstituted furanylene group, a substituted or unsubstituted benzofuranylene group, a substituted or unsubstituted thiophenylene group, a substituted or unsubstituted benzothiophenylene group, a substituted or unsubstituted thiazolylene group, a substituted or unsubstituted isothiazolylene group, a substituted or unsubstituted benzothiazolylene group, a substituted or unsubstituted isoxazolylene group, a substituted or unsubstituted oxazolylene group, a substituted or unsubstituted triazolylene group, a substituted or unsubstituted tetrazolylene group, a substituted or unsubstituted oxadiazolylene group, a substituted or unsubstituted triazinylene group, a substituted or unsubstituted benzooxazolylene group, a substituted or unsubstituted dibenzofuranylene group, a substituted or unsubstituted dibenzothiophenylene group, or a substituted or unsubstituted benzocarbazolyl group.

In some embodiments, Ar₁₀₁, Ar₁₀₂, Ar₁, and Ar₂ in Formulae 1 and 2 may be each independently a group represented by Formulae 3-1 to 3-24 below:

In Formulae 3-1 to 3-24, Y₁ may be O, S, C(R₂₁)(R₂₂), or N(R₂₃).

In Formulae 3-1 to 3-24, Z₁, Z₂, and R₂₁ to R₂₃ may be each independently selected from among hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a C₆-C₂₀ aryl group and a C₂-C₂₀ heteroaryl group; a C₆-C₂₀ aryl group and a C₂-C₂₀ heteroaryl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and —N(Q₁₁)(Q₁₂) and —Si(Q₁₃)(Q₁₄)(Q₁₅) (where Q₁₁ to Q₁₅ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₆-C₂₀ aryl group, or a C₂-C₂₀ heteroaryl group).

For example, Z₁, Z₂, and R₂₁ to R₂₃ may be each independently selected from among hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydra/one, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and —N(Q₁₁)(Q₁₂) and —Si(Q₁₃)(Q₁₄)(Q₁₅) (where Q₁₁ to Q₁₅ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, or an isoquinolyl group), but are not limited thereto.

In Formulae 3-1 to 3-24 above, *′ indicates a binding site, d1 may be an integer from 1 to 4; d2 may be an integer from 1 to 3; d3 may be an integer from 1 to 6; d4 may be an integer from 1 to 8; and d5 may be an integer of 1 or 2.

In some embodiments, Ar₁₀₁, Ar₁₀₂, Ar₁, and Ar₂ in Formulae 1 and 2 may be each independently a group represented by Formulae 4-1 to 4-7 below, but are not limited thereto:

In Formula 1 above, xa indicates number of Ar₁₀₁s, and xb indicates number of Ar₁₀₂s, wherein xa and xb may be each independently an integer from 0 to 5. When xa and/or xb is 0, “carbazole” and/or “fluorene” in Formula 1 may be linked directly to “N”. When xa is 2 or greater, the at least two of Ar₁₀₁s may be identical to or differ from each other. When xb is 2 or greater, the at least two of Ar₁₀₂s may be identical to or differ from each other.

In some embodiments, in Formula 1, i) xa=0 and xb=0; ii) xa=1 and xb=0; iii) xa=2 and xb=0; iv) xa=0 and xb=1; v) xa=0 and xb=2; or vi) xa=1 and xb=1, but not limited thereto.

In Formula 2, a indicates number of Ar₁s, and b indicates number of Ar₂s, wherein a and b may be each independently an integer from 0 to 5. When a and/or b is 0, “R₁” and/or “R₂” in Formula 2 may be linked directly to “N” of carbazole in Formula 2. When a is 2 or greater, the at least two of Ar₁s may be identical to or differ from each other. When b is 2 or greater, the at least two of Ar₂s may be identical to or differ from each other.

In some other embodiments, in Formula 2, i) a=0 and b=0; ii) a=1 and b=0; iii) a=0 and b=1; or iv) a=1 and b=1, but not limited thereto

In Formulae 1 and 2 above, R₁₀₁, R₁₀₉, R₁, and R₂ may be each independently a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, or a substituted or unsubstituted C₂-C₆₀ heteroaryl group.

For example, in Formulae 1 and 2 above, R₁₀₁, R₁₀₉, R₁, and R₂ may be each independently a substituted or unsubstituted phenyl group, a substituted or unsubstituted pentalenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted azulenyl group, a substituted or unsubstituted heptalenyl group, a substituted or unsubstituted indacenyl group, a substituted or unsubstituted acenaphthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spiro-fluorenyl group, a substituted or unsubstituted phenalenyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted anthryl group, a substituted or unsubstituted fluoranthenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted chrysenyl group, a substituted or unsubstituted naphthacenyl group, a substituted or unsubstituted picenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted pentaphenyl group, a substituted or unsubstituted hexacenyl group, a substituted or unsubstituted pyrrolyl group, a substituted or unsubstituted imidazolyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted pyridinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyridazinyl group, a substituted or unsubstituted isoindolyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted indazolyl group, a substituted or unsubstituted purinyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted benzoquinolinyl group, a substituted or unsubstituted phthalazinyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted cinnolinyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted phenanthridinyl group, a substituted or unsubstituted acridinyl group, a substituted or unsubstituted phenanthrolinyl group, a substituted or unsubstituted phenazinyl group, a substituted or unsubstituted benzooxazolyl group, a substituted or unsubstituted benzoimidazolyl group, a substituted or unsubstituted furanyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted thiophenyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted thiazolyl group, a substituted or unsubstituted isothiazolyl group, a substituted or unsubstituted benzothiazolyl group, a substituted or unsubstituted isoxazolyl group, a substituted or unsubstituted oxazolyl group, a substituted or unsubstituted triazolyl group, a substituted or unsubstituted tetrazolyl group, a substituted or unsubstituted oxadiazolyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted benzooxazolyl group, a substituted or unsubstituted dibenzopuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted benzocarbazolyl group.

In some other embodiments, R₁₀₁, R₁₀₉, R₁, and R₂ in Formulae 1 and 2 may be each independently a group represented by one of Formulae 5-1 to 5-22 below.

In Formulae 5-1 to 5-22, Y₂ may be O, S, C(R₂₅)(R₂₆), or N(R₂₇).

In Formulae 5-1 to 5-22, Z₁₁ to Z₁₄, and R₂₅ to R₂₇ may be each independently selected from among hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a C₆-C₂₀ aryl group, and a C₂-C₂₀ heteroaryl group; a C₆-C₂₀ aryl group and a C₂-C₂₀ heteroaryl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and —N(Q₁₁)(Q₁₂) and —Si(Q₁₃)(Q₁₄)(Q₁₅) (where Q₁₁ to Q₁₅ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₆-C₂₀ aryl group, or a C₂-C₂₀ heteroaryl group).

For example, Z₁₁ to Z₁₄, and R₂₅ to R₂₇ in Formulae 5-1 to 5-22 may be each independently selected from among hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and —N(Q₁₁)(Q₁₂) and —Si(Q₁₃)(Q₁₄)(Q₁₅) (where Q₁₁ to Q₁₅ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, or an isoquinolyl group, but are not limited thereto.

In Formulae 5-1 to 5-22, e1 may be an integer from 1 to 5; e2 may be an integer from 1 to 7; e3 may be an integer from 1 to 3; e4 may be an integer from 1 to 4; and e5 may be an integer of 1 or 2.

For example, R₁₀₁ in Formula 1 may be a group represented by one of Formulae 6-1 to 6-8 below, and R₁₀₉ in Formula 1 may be a group represented by one of Formulae Formula 6-1 to 6-11 below:

In Formulae 6-1 to 6-11, Z_(11a) to Z_(11c) may be defined the same as Z₁₁ described above, and R₂₅, R₂₆, Q₁₁, and Q₁₂ may be defined the same as described herein.

For example, in Formulae 6-1 to 6-11, Z_(11a) to Z_(11c), R₂₅, and R₂₆ may be each independently selected from among deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and Q₁₁ and Q₁₂ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, or an isoquinolyl group.

For example, R₁ and R₂ in Formula 2 may be each independently a group represented by one of Formulae 6-1 to 6-17 below:

In Formulae 6-1 to 6-17, Z_(11a) to Z_(11d) may be defined the same as Z₁₁ described above, and R₂₅, R₂₆, Q₁₁, and Q₁₂ may be defined the same as described herein.

For example, in Formulae 6-1 to 6-17, Z_(11a) to Z_(11d), and R₂₅ and R₂₆ may be each independently selected from among deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and Q₁₁ and Q₁₂ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, or an isoquinolyl group.

In some other embodiments, R₁₀₂ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₁ to R₁₄ may be each independently selected from hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₂-C₆₀ heteroaryl group, —N(Q₁)(Q₂), and —Si(Q₃)(Q₄)(Q₅) (where Q₁ to Q₅ are each independently a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a C₆-C₆₀ aryl group, or a C₂-C₆₀ heteroaryl group).

In Formula 2 above, c1 and c4 may be each independently an integer from 1 to 4; and c2 and c3 may be each independently an integer from 1 to 3.

In some other embodiments, R₁₀₂ to R₁₀₈, and R₁₁₁ to R₁₁₉ in Formula 1 above, and R11 to R14 in Formula 2 above may be each independently selected from among hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a sail thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, but are not limited thereto.

For example, R₁₀₂ to R₁₀₈ and R₁₁₃ to R₁₁₉ in Formula 1 above, and R₁₁ to R₁₄ in Formula 2 above may be hydrogen atoms.

In some embodiments, R₁₁₁ and R₁₁₂ in Formula 1 may be each independently selected from among a C₁-C₂₀ alkyl group; a C₁-C₂₀ alkyl group that is substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group.

In some embodiments, the first compound may be a compound represented by Formula 1A, 1B, or 1C below, and the second compound may be a compound represented by Formula 2A, 2B, or 2C below:

In Formulae 1A, 1B, 1C, 2A, 2B, and 2C, Ar₁₀₁, Ar₁₀₂, xa, xb, R₁₀₁ to R₁₀₉, R₁₁₁ to R₁₁₉, Ar₁, Ar₂, R₁, R₂, R₁₁ to R₁₄, a, b, c1, c2, c3, and c4 may be defined the same as described herein.

For example, in Formulae 1A, 1B, and 1C, Ar₁₀₁ and Ar₁₀₂ may be each independently a group represented by one of Formulae 3-1 to 3-24; xa and xb may be each independently 1 or 2; R₁₀₁ and R₁₀₉ may be each independently a group represented by one of Formulae 5-1 to 5-22.

For example, in Formulae 1A, 1B, and 1C, R₁₁₁ and R₁₁₂ may be each independently one of a C₁-C₂₀ alkyl group; a C₁-C₂₀ alkyl group substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxy group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazine, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and R₁₀₂ to R₁₀₈ and R₁₁₃ to R₁₁₉ may be each independently selected from hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, but are not limited thereto.

For example, in Formulae 1A, 1B, and 1C, Ar₁₀₁ and Ar₁₀₂ may be each independently a group represented by one of Formulae 4-1 to 4-7; xa and xb may be each independently 1 or 2; R₁₀₁ may be a group represented by one of Formulae 6-1 to 6-8; R₁₀₉ may be a group represented by one of Formulae 6-1 to 6-11; R₁₁₁ and R₁₁₂ may be each independently one of a C₁-C₂₀ alkyl group; a C₁-C₂₀ alkyl group that is substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group that are substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and R₁₀₂ to R₁₀₈ and R₁₁₃ to R₁₁₉ may be hydrogen atoms.

In some embodiments, in Formulae 2A, 2B, and 2C, Ar₁ and Ar₂ may be each independently a group represented by one of Formulae 3-1 to 3-24; i) a=0 and b=0, ii) a=1 and b=0, iii) a=0 and b=1, or iv) a=1 and b=1; R₁ and R₂ may be each independently a group represented by one of Formulae 5-1 to 5-22; and R₁₁ to R₁₄ may be each independently one of hydrogen, deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group that are substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, but not limited thereto.

In some other embodiments, in Formulae 2A, 2B, and 2C, Ar₁ and Ar₂ may be each independently a group represented by one of Formulae 4-1 to 4-7; i) a=0 and b=0, ii) a=1 and b=0, iii) a=0 and b=1, or iv) a=1 and b=1; R₁ and R₂ may be each independently a group represented by one of Formulae 6-1 to 6-17; and R₁₁ to R₁₄ may be hydrogen atoms, but not limited thereto.

In some embodiments, the first compound of Formula 1 above may include one of Compounds 1-1 to 1-19 below, but is not limited thereto:

In some embodiments, the second compound of Formula 2 above may include one of Compounds 2-1 to 2-25 below, but is not limited thereto:

At least one substituent of the substituted C₃-C₁₀ cycloalkylene group, the substituted C₂-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₂-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₂-C₆₀ heteroarylene group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₂-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₂-C₆₀ heteroaryl group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₆-C₆₀ aryloxy group, and the substituted C₆-C₆₀ arylthio group may be selected from among deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₃-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, and a C₂-C₆₀ heteroaryl group; a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₃-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, and a C₂-C₆₀ heteroaryl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and —Si(Q₁₃)(Q₁₄)(Q₁₅) (where Q₁₃ to Q₁₅ may be each independently a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a C₆-C₆₀ aryl group, or a C₂-C₆₀ heteroaryl group), but not limited thereto.

The first compound of Formula 1 above has good charge (hole) transporting ability. The second compound of Formula 2 above has good charge (hole) transporting ability, good light-emitting ability, and has a high band gap energy between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), and thus allows easy energy level adjustment. When including the first compound in the hole migration region 13 and the second compound in at least one of the hole migration region 13 and the EML 15, the organic light-emitting diode 10 may have a low driving voltage, a high luminance, a high efficiency, and a long lifetime.

In some embodiments, the first compound of Formula 1 and the second compound of Formula 2 may be both in the hole migration region 13.

In some other embodiments, the first compound of Formula 1 above may be in the hole migration region 13, and the second compound of Formula 2 above may be in the EML 15.

In some other embodiments, the first compound of Formula 1 above and the second compound of Formula 2 above may be both in the hole migration region 13, and only the second compound of Formula 2 above may be in the EML 15. In this regard, the second compound in the hole migration region 13 and the second compound in the EML 15 may be the same or differ from each other.

FIG. 2 is a schematic view of a structure of an organic light-emitting diode 20 according to another embodiment of the present invention. Referring to FIG. 2, the organic light emitting diode 20 may have a structure including a substrate 21, a first electrode 22, a hole migration region 23, an emission layer (EML) 25, an electron migration region 27, and a second electrode 29 that are sequentially stacked on one another.

The hole migration region 23 may include a hole injection layer (HIL) 23A, a first hole transport layer (HTL) 23B-1, and a second HTL 23B-2 that are sequentially stacked on the first electrode 22. The electron migration region 27 may include an electron transport layer (ETL) 27A and an electron injection layer (EIL) 27B that are sequentially stacked on the EML 25.

The above-detailed descriptions of the substrate 11, the first electrode 12, and the second electrode 19 may be referred to as detailed descriptions of the substrate 21, the first electrode 22, and the second electrode 29 of FIG. 2.

The HIL 23A may be formed on the first electrode 22 by any of a variety of methods, including vacuum deposition, spin coating, casting, and Langmuir-Blodgett (LB) deposition.

When the HIL 23A is formed using vacuum deposition, vacuum deposition conditions may vary according to the compound that is used to form the HIL 23A, and the desired structure and thermal properties of the HIL 23A to be formed. For example, vacuum deposition may be performed at a temperature of about 100° C. to about 500° C., a pressure of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition rate of about 0.01 Å/sec to about 100 Å/sec. However, the deposition conditions are not limited thereto.

When the HIL 23A is formed using spin coating, the coating conditions may vary according to the compound that is used to form the HIL 23A, and the desired structure and thermal properties of the HIL 23A to be formed. For example, the coating rate may be in the range of about 2000 rpm to about 5000 rpm, and a temperature at which heat treatment is performed to remove a solvent after coating may be in the range of about 80° C. to about 200° C. However, the coating conditions are not limited thereto.

Non-limiting examples of materials for the HIL 23A may be N,N′-diphenyl-N,N′-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4′-diamine, (DNTPD), a phthalocyanine compound such as copperphthalocyanine, 4,4′,4″-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), TDATA, 2-TNATA, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (Pani/CSA), and polyaniline)/poly(4-styrenesulfonate (PANI/PSS).

The thickness of the HIL 23A may be from about 100 Å to about 10000 Å, and in some embodiments, may be from about 100 Å to about 1000 Å. When the thickness of the HIL 23A is within these ranges, the HIL 23A may have good hole injecting ability without a substantial increase in driving voltage.

Then, a first HTL 23B-1 may be formed on the HIL 23A by using any of a variety of methods, for example, vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, or the like. When the first HTL 23B-1 is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL 23A, although the conditions for the deposition and coating may vary depending on the material that is used to form the first HTL 23B-1.

The first HTL 23B-1 may be formed of the first compound represented by Formula 1 above. The above-detailed description of Formula 1 above may be referred to here. For example, the first HTL 23B-1 may include a first compound represented by Formula 1A, 1B, or 1C above, wherein, in Formula 1A, 1B, and 1C, Ar₁₀₁ and Ar₁₀₂ may be each independently a group represented by one of Formulae 4-1 to 4-7; xa and xb may be each independently 1 or 2; R₁₀₁ may be a group represented by one of Formulae 6-1 to 6-8; R₁₀₉ may be a group represented by one of Formulae 6-1 to 6-11; R₁₁₁ and R₁₁₂ may be each independently one of a C₁-C₂₀ alkyl group; a C₁-C₂₀ alkyl group that is substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and R₁₀₂ to R₁₀₈ and R₁₁₃ to R₁₁₉ may be hydrogen atoms.

In some other embodiments, a material for the first HTL 23B-1 may be one of Compounds 1-1 to 1-19 above.

Then, a second HTL 23B-2 may be formed on the first HIL 23B-1 by using any of a variety of methods, for example, vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, or the like. When the second HTL 23B-2 is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL 23A, although the conditions for the deposition and coating may vary depending on the material that is used to form the second HTL 23B-2.

A material for the second HTL 23B-2 may be a second compound represented by Formula 2 above. The above-detailed description of Formula 2 above may be referred to here. For example, the second HTL 23B-2 may include a second compound represented by Formula 2A, 2B or 2C, wherein, in Formula 2A, 2B and 2C, Ar₁ and Ar₂ may be each independently a group represented by one of Formulae 4-1 to 4-7; i) a=0 and b=0, ii) a=1 and b=0, iii) a=0 and b=1, or iv) a=1 and b=1; R₁ and R₂ may be each independently a group represented by one of Formulae 6-1 to 6-17; R₁₁ to R₁₄ may be hydrogen atoms; c1 and c4 may be each independently an integer from 1 to 4; and c2 and c3 may be each independently an integer from 1 to 3. In the Formulae 6-1 to 6-17, Z_(11a) to Z_(11d), R₂₅ and R₂₆ may be each independently selected from among deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and Q₁₁ and Q₁₂ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, or an isoquinolyl group.

In some other embodiments, the second HTL 23B-2 may include one of Compounds 2-1 to 2-25 above, but is not limited thereto.

A total of thicknesses of the first HTL 23B-1 and the second HTL 23B-2 may be from about 50 Å to about 2000 Å, and in some embodiments, from about 100 Å to about 1500 Å. When the total of thicknesses of the first HTL 23B-1 and the second HTL 23B-2 is within these ranges, the first HTL 23B-1 and second HTL 23B-2 may have satisfactory hole transporting ability without a substantial increase in driving voltage.

A thickness ratio of the first HTL 23B-1 to the second HTL 23B-2 may be from about 1:9 to about 9:1, and in some embodiments, from about 3:7 to about 7:3, but is not limited thereto.

At least one of the HIL 23A, the first HTL 23B-1, and the second HTL 23B-2 may further include a charge-generating material, in addition to the above-described materials, to improve conductivity of the layers.

The charge-generating material may be, for example, a p-type dopant. The p-type dopant may be one of quinine derivatives, metal oxides, and compounds with a cyano group, but are not limited thereto. Non-limiting examples of the p-type dopant may be quinone derivatives such as tetracyanoquinonedimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), and the like; metal oxides such as tungsten oxide, molybdenum oxide, and the like; and cyano-containing compounds such as Compound 200 below.

The charge-generating material may be homogeneously dispersed or inhomogeneously distributed in at least one of the HIL 23A, the first HTL 23B-1 and the second HTL 23B-2. The charge-generating material may be present in any form.

Then, the EML 25 may be formed on the second HTL 23B-2 by using vacuum deposition, spin coating, casting, LB deposition, or the like. When the EML 25 is formed using vacuum deposition or spin coating, the deposition and coating conditions may be similar to those for the formation of the HIL 23A, though the conditions for deposition and coating may vary depending on the material that is used to form the EML 25.

The EML 25 may include a host and a dopant,

Non-limiting examples of the host may be Alq₃, 4,4′-N,N′-dicarbazole-biphenyl (CBP), poly(n-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), TCTA, 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI), 3-tert-butyl-9,10-di-2-naphthylanthracene (TBADN), E3, distyrylarylene (DSA), dmCBP (see a formula below), and Compounds 501 to 509 below.

In some embodiments, an anthracene-based compound represented by Formula 400 below may be used as the host.

In Formula 400, Ar₁₁₁ and Ar₁₁₂ may be each independently a substituted or unsubstituted C₆-C₆₀ arylene group; Ar₁₁₃ to Ar₁₁₆ may be each independently a substituted or unsubstituted C₁-C₁₀ alkyl group or a substituted or unsubstituted C₆-C₆₀ aryl group; and g, h, I, and j may be each independently an integer from 0 to 4.

In some embodiments, Ar₁₁₁ and Ar₁₁₂ in Formula 400 may be each independently selected from a phenylene group, a naphthylene group, a phenanthrenylene group, and a pyrenylene group; and a phenylene group, a naphthylene group, a phenanthrenylene group, a fluorenyl group, and a pyrenylene group, substituted with at least one of a phenyl group, a naphthyl group, and an anthryl group.

In Formula 400 above, g, h, I, and j may be each independently 0, 1, or 2.

In some embodiments, Ar₁₁₃ to Ar₁₁₆ in Formula 400 may be each independently one of a C₁-C₁₀ alkyl group substituted with at least one of a phenyl group, a naphthyl group, and an anthryl group; a phenyl group; a naphthyl group; an anthryl group; a pyrenyl group; a phenanthrenyl group; a fluorenyl group; a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group; and

but are not limited thereto.

For example, the anthracene-based compound of Formula 400 above may be one of the compounds represented by the following formulae, but is not limited thereto:

In some embodiments, an anthracene-based compound represented by Formula 401 below may be used as the host.

Ar₁₂₂ to Ar₁₂₅ in Formula 401 above may be defined as described above in conjunction with Ar₁₁₃ of Formula 400, and thus detailed descriptions thereof will not be provided here. Ar₁₂₆ and Ar₁₂₇ in Formula 401 above may be each independently a C₁-C₁₀ alkyl group, for example, a methyl group, an ethyl group, or a propyl group. In Formula 401, k and l may be each independently an integer from 0 to 4, for example, 0, 1, or 2.

For example, the anthracene compound of Formula 401 above may be one of the compounds represented by the following formulae, but is not limited thereto:

The EML 25 may include the second compound represented by Formula 2 above as a host. When the EML 25 includes the second compound of Formula 2 as a host, the host in the EML 25 and the material of the second HTL 23B-2 may be the same or differ from each other.

When the organic light-emitting diode is a full color organic light-emitting diode, the second electrode may be patterned into a red second electrode, a green second electrode, and a blue second electrode. In some embodiments, the organic light-emitting diode may include a red second electrode, a green second electrode, and/or a blue second electrode that are stacked upon one another to emit white light, but is not limited thereto.

The dopant in the EML 25 may be a known dopant. Non-limiting examples of the blue dopant may be compounds represented by the following formulae.

Non-limiting examples of red dopant in the EML 25 may be compounds represented by the following formulae. In some embodiments, the red dopant may be DCM or DCJTB, which will be described later.

Non-limiting examples of green dopant in the EML 25 may be compounds represented by the following formulae. In an embodiment, the green dopant may be C545T represented below.

Non-limiting examples of the dopant that may be used in the EML 25 may be complexes represented by the following formulae:

Non-limiting examples of the dopant that may be used in the EML 25 may be Os complexes represented by the following formulae:

When the EML 25 includes both a host and a dopant, the amount of the dopant may be, but is not limited to, from about 0.01 to about 15 parts by weight based on 100 parts by weight of the host.

A thickness of the EML 25 may be from about 100 Å to about 1000 Å, and in some embodiments, may be from about 200 Å to about 600 Å. When the thickness of the EML 25 is within these ranges, the EML 25 may have improved light-emitting ability without a substantial increase in driving voltage.

Then, an ETL 27A may be formed on the EML 25 using any of a variety of methods, such as vacuum deposition, spin coating, casting, or the like. When the ETL 27A is formed using vacuum deposition or spin coating, the deposition and coating conditions may be similar to those for the formation of the HIL 23A, though the deposition and coating conditions may vary depending on the material that is used to form the ETL 23A. A material for forming the ETL 27A may be any known material that can stably transport electrons injected from the second electrode 29. Non-limiting examples of materials for forming the ETL 27A may be a quinoline derivative, such as tris(8-quinolinorate)aluminum (Alq3), TAZ, BAlq, beryllium bis(benzoquinolin-10-olate (Bebq₂), 9,10-di(naphthalene-2-yl)anthracene (ADN), Compound 201, and Compound 202, but are not limited thereto.

The thickness of the ETL 27A may be from about 100 Å to about 1,000 Å, and in some embodiments, may be from about 150 Å to about 500 Å. When the thickness of the ETL 27A is within these ranges, the ETL 237A may have satisfactory electron transporting ability without a substantial increase in driving voltage.

The ETL 27A may further include a metal-containing material, in addition to such an electron transporting organic material as described above.

The metal-containing material may include a lithium (Li) complex. Non-limiting examples of the Li complex are lithium quinolate (LiQ) and Compound 203 below:

Then, an EIL 27B, which facilitates injection of electrons from the anode, may be formed on the ETL 27A. Any suitable electron-injecting material may be used to form the EIL 27B.

Non-limiting examples of materials for forming the EIL 27B may be LiF, NaCl, CsF, Li₂O, and BaO, which are known in the art. The deposition and coating conditions for forming the EIL 27B may be similar to those for the formation of the HIL 23A, though the deposition and coating conditions may vary according to the material that is used to form the EIL 27B.

The thickness of the EIL 27B may be from about 1 Å to about 100 Å, and in some embodiments, may be from about 3 Å to about 90 Å. When the thickness of the EIL 27B is within these ranges, the EIL 27B may have satisfactory electron injection ability without a substantial increase in driving voltage.

FIG. 3 is a schematic view of a structure of an organic light-emitting diode 30 according to another embodiment of the present invention. Referring to FIG. 3, the organic light emitting diode 30 has a structure including a substrate 31, a first electrode 32, a hole migration region 33, an EML 35, an electron migration region 37, and a second electrode 39 that are sequentially stacked on one another. The hole migration region 33 may include a HIL 33A and a HTL 33B that are sequentially stacked on the first electrode 32. The electron migration region 37 may include an ETL 37A and an EIL 37B that are sequentially stacked on the EML 35.

The above-detailed descriptions of the substrate 21, the first electrode 22, the HIL 23A, the ETL 27A, the EIL 27B, and the second electrode 29 may be referred to as detailed descriptions of the substrate 31, the first electrode 32, the HIL 33A, the ETL 37A, the EIL 38B, and the second electrode 39 of FIG. 3.

A material for the HTL 33B may be a first compound represented by Formula 1 above. The above-detailed description of Formula 1 above may be referred to here. For example, the HTL 33B may include a first compound of the Formula 1A, 1B, or 1C, wherein, in Formulae 1A, 1B and 1C, Ar₁₀₁ and Ar₁₀₂ may be each independently a group represented by one of Formulae 4-1 to 4-7; xa and xb may be each independently 1 or 2; R₁₀₁ may be a group represented by one of Formulae 6-1 to 6-8; R₁₀₉ may be a group represented by one of Formulae 6-1 to 6-11; R₁₁₁ and R₁₁₂ may be each independently one of a C₁-C₂₀ alkyl group; a C₁-C₂₀ alkyl group that is substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group that are substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and R₁₀₂ to R₁₀₈ and R₁₁₃ to R₁₁₉ may be hydrogen atoms.

In some embodiments, a material for the HTL 33B may be one of Compounds 1-1 to 1-19 above.

The thickness of the HTL 33B may be from about 50 Å to about 2000 Å, and in some embodiments, may be from about 100 Å to about 1500 Å. When the thickness of the HTL 33B is within these ranges, the HTL 33B may have satisfactory hole transporting ability without a substantial increase in driving voltage.

At least one of the HIL 33A and the HTL 33B may further include a charge-generating material as described above.

The EML 35 may include a host and a dopant, the dopant may include a second compound represented by Formula 2 above. The above-detailed description of Formula 2 above may be referred to here. For example, the EML 35 may include a second compound of Formula 2A, 2B, or 2C as the host, wherein, in Formulae 2A, 2B, and 2C, Ar₁ and Ar₂ may be each independently a group represented by one of Formulae 4-1 to 4-7; i) a=0 and b=0, ii) a=1 and b=0, iii) a=0 and b=1, or iv) a=1 and b=1; R₁ and R₂ may be each independently a group represented by one of Formulae 6-1 to 6-17; R₁₁ to R₁₄ may be hydrogen atoms; c1 and c4 may be each independently an integer from 1 to 4; and c2 and c3 may be each independently an integer from 1 to 3. In the Formulae 6-1 to 6-17, Z_(11a) to Z_(11d), R₂₅ and R₂₆ may be each independently selected from among deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group; a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and Q₁₁ and Q₁₂ may be each independently a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, or an isoquinolyl group.

In some embodiments, the EML 35 may include one of Compounds 2-1 to 2-25 above as the host, but is not limited thereto.

The above-detailed descriptions on the dopant and thickness of the EML 25 of FIG. 2 may be referred to here as descriptions of the dopant and thickness of the EML 35 of FIG. 3.

Although described with reference to the organic light-emitting diodes 10, 20, and 30 of FIGS. 1, 2, and 3, the embodiments of the present invention are not limited thereto. Although not shown in FIGS. 2 and 3, a buffer layer may be further disposed between the second HTL 23B-2 and the EML 25 of FIG. 2, or between the HTL 33B and the EML 35 of FIG. 3 in order to compensate for an optical resonance distance according to the wavelength of light emitted from the EML 25 or the EML 35 for higher efficiency. The buffer layer may include a known hole injection material, a known hole transporting material, the first compound of Formula 1 above, or the second compound of Formula 2 above.

When the EML 25 or the EML 35 includes a phosphorescent dopant, a hole blocking layer (HBL) may be disposed between the EML 25 and the ETL (27A) of FIG. 2, or between the EML 35 and the ETL 37A of FIG. 3, in order to prevent diffusion of triplet exitons or holes into the ETL 27A or the ETL 37A. When the HBL is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL, although the conditions for deposition and coating may vary according to the material that is used to form the HBL. Any known hole-blocking material may be used. Non-limiting examples of hole-blocking materials may be oxadiazole derivatives, triazole derivatives, and phenanthroline derivatives. For example, bathocuproine (BCP) represented by the following formula may be used as a material for forming the HBL.

The thickness of the HBL may be from about 20 Å to about 1000 Å, and in some embodiments, may be from about 30 Å to about 300 Å. When the thickness of the HBL is within these ranges, the HBL may have improved hole blocking ability without a substantial increase in driving voltage.

In some embodiments, the HIL 23A of FIG. 2 and/or the HIL 33A of FIG. 3 may not be included. However, embodiments of the present invention are not limited thereto, and may include any of a variety of structures.

As used herein, the unsubstituted C₁-C₆₀ alkyl group (or a C₁-C₆₀ alkyl group) may be a linear or branched C₁-C₆₀ alkyl group, including a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. The substituted C₁-C₆₀ alkyl group may include at least one substituent selected from among deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid group or a salt thereof; a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₃-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, and a C₂-C₆₀ heteroaryl group; a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₃-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, and a C₂-C₆₀ heteroaryl group that are substituted with at least one of deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, hydrazine, hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a dimethylfuorenyl group, a diphenylfluorenyl group, a carbazolyl group, a phenylcarbazolyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolyl group, and an isoquinolyl group; and —N(Q₁₁)(Q₁₂) and —Si(Q₁₃)(Q₁₄)(Q₁₅) (where Q₁₁ and Q₁₂ may be each independently a C₆-C₆₀ aryl group, or a C₂-C₆₀ heteroaryl group, and Q₁₃ to Q₁₅ may be each independently a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a C₆-C₆₀ aryl group, or a C₂-C₆₀ heteroaryl group), but is not limited thereto.

As used herein, the unsubstituted C₁-C₆₀ alkoxy group (or a C₁-C₆₀ alkoxy group) may be represented by —OA (where A indicates a C₁-C₆₀ alkyl group as described above), and may be, for example, a methoxy group, an ethoxy group, or an isopropoxy group. At least one hydrogen atoms of these alkyl groups may be substituted with those substituents described above in conduction with the substituted C₁-C₆₀ alkyl group.

As used herein, the unsubstituted C₂-C₆₀ alkenyl group (or a C₂-C₆₀ alkenyl group) means as a C₂-C₆₀ alkyl group as described above with at least one carbon double bond in the middle or terminal thereof. Examples of the alkenyl group may be an ethenyl group, a propenyl group, a butenyl group, and the like. At least one hydrogen atom in the unsubstituted C₂-C₆₀ alkenyl group may be substituted with those substituents described above in conjunction with the substituted C₁-C₆₀ alkyl group.

The unsubstituted C₂-C₆₀ alkynyl group may be a C₂-C₆₀ alkyl group having at least one carbon-carbon triple bond in the center or at a terminal thereof. Examples of the unsubstituted C₂-C₆₀ alkynyl group may be an ethenyl group, a propynyl group, and the like. At least one hydrogen atom in the alkynyl group may be substituted with those substituents described above in conjunction with the substituted C₁-C₆₀ alkyl group.

The unsubstituted C₆-C₆₀ aryl group may be monovalent carbocyclic aromatic system having 6 to 60 carbon atoms including at least one aromatic ring. The unsubstituted C₆-C₆₀ arylene group may be a divalent group having a divalent carbocyclic aromatic system having 6 to 60 carbon atoms including at least one aromatic ring. When the aryl group and the arylene group have at least two rings, they may be fused to each other via a single bond. At least one hydrogen atom in the aryl group and the arylene group may be substituted with those substituents described above in conjunction with the C₁-C₆₀ alkyl group.

Examples of the substituted or unsubstituted C₆-C₆₀ aryl group may be a phenyl group, a C₁-C₁₀ alkylphenyl group (e.g., an ethylphenyl group), a C₁-C₁₀ alkylbiphenyl group (e.g., an ethylbiphenyl group), a halophenyl group (e.g., an o-, m- or p-fluorophenyl group and a dichlorophenyl group), a dicyanophenyl group, a trifluoromethoxyphenyl group, an o-, m- or p-tolyl group, an o-, m- or p-cumenyl group, a mesityl group, a phenoxyphenyl group, a (α,α-dimethylbenzene)phenyl group, a (N,N′-dimethyl)aminophenyl group, a (N,N′-diphenyl)aminophenyl group, a pentalenyl group, an indenyl group, a naphthyl group, a halonaphthyl group (e.g., a fluoronaphthyl group), a C₁-C₁₀ alkylnaphthyl group (e.g., a methylnaphthyl group), a C₁-C₁₀ alkoxynaphthyl group (e.g., a methoxynaphthyl group), an anthracenyl group, an azulenyl group, a heptalenyl group, an acenaphthylenyl group, a phenalenyl group, a fluorenyl group, an anthraquinolyl group, a methylanthryl group, a phenanthryl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, an ethyl-chrysenyl group, a picenyl group, a perylenyl group, a chloroperylenyl group, a pentaphenyl group, a pentacenyl group, a tetraphenylenyl group, a hexaphenyl group, hexacenyl group, a rubicenyl group, a coronenyl group, a trinaphthylenyl group, a heptaphenyl group, a heptacenyl group, a pyranthrenyl group, and an ovalenyl group. Examples of the substituted C₆-C₆₀ aryl group may be inferred based on those of the unsubstituted C₆-C₆₀ aryl group and the substituted C₁-C₃₀ alkyl group described above. Examples of the substituted or unsubstituted C₆-C₆₀ arylene group may be inferred based on those examples of the substituted or unsubstituted C₆-C₆₀ aryl group described above.

The unsubstituted C₂-C₆₀ heteroaryl group may be a monovalent group having at least one aromatic ring having at least one of the heteroatoms selected from the group consisting of N, O, P, and S. The unsubstituted C₂-C₆₀ heteroarylene group may be a divalent group having at least one aromatic ring having at least one of the heteroatoms selected from the group consisting of N, O, P, and S. In this regard, when the heteroaryl group and the heteroarylene group have at least two rings, they may be fused to each other via a single bond. At least one hydrogen atom in the heteroaryl group and the heteroarylene group may be substituted with those substituents described with reference to the C₁-C₆₀ alkyl group.

Examples of the unsubstituted C₂-C₆₀ heteroaryl group may be a pyrazolyl group, an imidazolyl group, an oxazolyl group, a thiazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a pyridinyl group, a pyridazinyl group, a pyrimidinyl group, a triazinyl group, a carbazolyl group, an indolyl group, a quinolinyl group, an isoquinolinyl group, a benzoimidazolyl group, an imidazopyridinyl group and an imidazopyrimidinyl group. Examples of the substituted or unsubstituted C₂-C₆₀ heteroarylene group may be inferred based on those examples of the substituted or unsubstituted C₂-C₆₀ arylene group described above.

The substituted or unsubstituted C₆-C₆₀ aryloxy group may indicate —OA₂ (where A₂ is a substituted or unsubstituted C₆-C₆₀ aryl group described above). The substituted or unsubstituted C₅-C₆₀ arylthiol group may indicate —SA₃ (where A₃ is a substituted or unsubstituted C₆-C₆₀ aryl group described above).

Hereinafter, the present invention will be described in detail with reference to the following synthesis examples and other examples. However, these examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

EXAMPLES Example 1

To manufacture an anode, a glass substrate with deposited ITO/Ag/ITO layers (70/1000/70 Å) was cut to a size of 50 mm×50 mm×0.5 mm and then ultrasonicated in isopropyl alcohol and pure water each for five minutes, and then cleaned by irradiation of ultraviolet rays for 30 minutes and exposure to ozone. The resulting glass substrate was loaded into a vacuum deposition device.

After 2-TNATA was vacuum-deposited on the anode to form an HIL having a thickness of about 600 Å, Compound 1-5 was vacuum-deposited on the HIL to form a first HTL having a thickness of about 600 Å, and Compound 2-1 was deposited on the first HTL to form a second HTL having a thickness of about 400 Å.

After CBP(host) and Ir(ppy)₃ were co-deposited in a weight ratio of about 91:9 on the second HTL to form an EML having a thickness of about 250 Å, followed by depositing BCP on the EML to form a hole-blocking layer having a thickness of about 50 Å. After deposition of Alq₃ on the hole-blocking layer to form an electron transport layer having a thickness of about 350 Å, LiF was deposited on the electron transport layer to form an electron injecting layer having a thickness of about 10 Å, followed by depositing Mg and Al in a weight ratio of about 90:10 on the electron injection layer to form a cathode having a thickness of about 120 Å, thereby completing the manufacture of the organic light-emitting diode (emitting green light).

Example 2

An organic light-emitting diode was manufactured in the same manner as in Example 1, except that Compound 1-19, instead of Compound 1-5, was used to form the first HTL, and Compound 2-19, instead of Compound 2-1, was used to form the second HTL.

Example 3

To manufacture an anode, a glass substrate with deposited ITO/Ag/ITO layers (70/1000/70 Å) was cut to a size of 50 mm×50 mm×0.5 mm and then ultrasonicated in isopropyl alcohol and pure water each for five minutes, and then cleaned by irradiation of ultraviolet rays for 30 minutes and exposure to ozone. The resulting glass substrate was loaded into a vacuum deposition device.

After 2-TNATA was vacuum-deposited on the anode to form an HIL having a thickness of 600 Å, Compound 1-5 was vacuum-deposited on the HIL to form a first HTL having a thickness of 600 Å, and Compound 2-7 was deposited on the first HTL to form a second HTL having a thickness of about 750 Å.

CBP (host) and PtOEP were co-deposited in a weight ratio of about 91:9 on the second HTL to form an EML having a thickness of about 400 Å, followed by depositing BCP on the EML to form a hole-blocking layer having a thickness of about 50 Å. After deposition of Alq₃ on the hole-blocking layer to form an ETL having a thickness of about 350 Å, LiF was deposited on the ETL to form an EIL having a thickness of about 10 Å, followed by depositing Mg and Al in a weight ratio of about 90:10 on the EIL to form a cathode having a thickness of about 120 Å, thereby completing the manufacture of the organic light-emitting diode (emitting red light).

Example 4

An organic light-emitting diode was manufactured in the same manner as in Example 3, except that Compound 1-17, instead of Compound 1-5, was used to form the first HTL, and Compound 2-19, instead of Compound 2-7, was used to form the second HTL.

Example 5

An organic light-emitting diode (emitting green light) was manufactured in the same manner as in Example 1, except that, instead of forming the first HTL and the second HTL on the HIL, Compound 1-5 was deposited to form a HTL having a thickness of about 1000 Å, and Compound 2-7 (host) and Ir(ppy)₃ were co-deposited on the HTL in a weight ratio of 91:9 to form an EML having a thickness of about 250 Å.

Example 6

An organic light-emitting diode was manufactured in the same manner as in Example 5, except that Compound 1-17, instead of Compound 1-5, was used to form the HTL, and Compound 2-10, instead of Compound 2-7, was used as a host in forming the EML.

Example 7

An organic light-emitting diode (emitting red light) was manufactured in the same manner as in Example 3, except that, instead of forming the first HTL and the second HTL on the HIL, Compound 1-5 was deposited to form a HTL having a thickness of about 1350 Å, and Compound 2-10 (host) and PtOEP were co-deposited on the HTL in a weight ratio of 91:9 to form an EML having a thickness of about 400 Å.

Example 8

An organic light-emitting diode was manufactured in the same manner as in Example 7, except that Compound 1-19, instead of Compound 1-5, was used to form the HTL, and Compound 2-19, instead of Compound 2-10, was used as a host in forming the EML.

Comparative Example 1

An organic light-emitting diode was manufactured in the same manner as in Example 5, except that Compound A represented by Formula A below, instead of Compound 1-5, was used to form the HTL, and CBP, instead of Compound 2-7, was used as a host in forming the EML.

Comparative Example 2

An organic light-emitting diode was manufactured in the same manner as in Example 7, except that Compound A of Formula A above, instead of Compound 1-5, was used to form the HTL, and CBP, instead of Compound 2-10, was used as a host in forming the EML.

Evaluation Example 1

Driving voltages, luminances, emitting-light colors, efficiencies, and half-life spans (@10 mA/cm²) of the organic light-emitting diodes of Examples 1 to 8 and Comparative Examples 1 and 2 were measured using a PR650 (Spectroscan) Source Measurement Unit (available from Photo Research, Inc.). The results are shown in Tables 1 and 2 below. LT₉₇ lifetime indicates the time taken until a measured initial luminosity (assumed as 100%) is reduced to 97%.

TABLE 1 HTL Driving Current Second voltage density Luminance Example First HTL HTL Host Dopant (V) (mA/cm²) (cd/m²) Example 1 Compound Compound CBP Ir(ppy)₃ 5.1 10 6,233 1-5 2-1 Example 2 Compound Compound CBP Ir(ppy)₃ 5.2 10 6,592 1-19 2-19 Example 3 Compound Compound CBP PtOEP 5.6 10 3,051 1-5 2-7 Example 4 Compound Compound CBP PtOEP 5.5 10 2,817 1-17 2-19 Example 5 Compound 1-5 Compound Ir(ppy)₃ 5.0 10 6,184 2-7 Example 6 Compound 1-17 Compound Ir(ppy)₃ 5.3 10 6,292 2-10 Example 7 Compound 1-5 Compound PtOEP 5.8 10 3,437 2-10 Example 8 Compound 1-19 Compound PtOEP 5.6 10 2,918 2-19 Comparative Compound A CBP Ir(ppy)₃ 6.7 10 4,551 Example 1 Comparative Compound A CBP PtOEP 7.1 10 2,009 Example 2

TABLE 2 HTL First Second Efficiency Emission LT₉₇ Example HTL HTL Host Dopant (cd/A) color (hr) Example 1 Compound Compound CBP Ir(ppy)₃ 62.3 Green 81 1-5 2-1 Example 2 Compound Compound CBP Ir(ppy)₃ 65.9 Green 84 1-19 2-19 Example 3 Compound Compound CBP PtOEP 30.5 Red 130 1-5 2-7 Example 4 Compound Compound CBP PtOEP 28.2 Red 132 1-17 2-19 Example 5 Compound 1-5 Compound Ir(ppy)₃ 61.8 Green 77 2-7 Example 6 Compound 1-17 Compound Ir(ppy)₃ 62.9 Green 79 2-10 Example 7 Compound 1-5 Compound PtOEP 34.4 Red 135 2-10 Example 8 Compound 1-19 Compound PtOEP 29.2 Red 128 2-19 Comparative Compound A CBP Ir(ppy)₃ 45.5 Green 60 Example 1 Comparative Compound A CBP PtOEP 20.1 Red 102 Example 2

Referring to Tables 1 and 2, the organic light-emitting diodes of Examples 1 to 8 were found to have lower driving voltages, higher luminance, higher efficiencies, higher color purity, and better lifetime characteristics, as compared to the organic light-emitting diodes of Comparative Examples 1 and 2.

As described above, according to the one or more of the above embodiments of the present invention, an organic light-emitting diode may have a low driving voltage, a high efficiency, and a long lifetime.

It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. 

What is claimed is:
 1. An organic light-emitting diode comprising: a substrate; a first electrode on the substrate; a second electrode disposed opposite to the first electrode; an emission layer disposed between the first electrode and the second electrode; a hole migration region disposed between the first electrode and the emission layer; and an electron migration region disposed between the emission layer and the second electrode, wherein the hole migration region comprises a first compound represented by Formula 1-5 or Formula 1-8 and at least one of the hole migration region and the emission layer comprises a second compound represented by Formula 2-1, Formula 2-2, Formula 2-7, or Formula 2-10:


2. The organic light-emitting diode of claim 1, wherein the hole migration region comprises i) a first hole transport layer, and ii) a second hole transport layer disposed between the first hole transport layer and the emission layer; and the first compound is in the first hole transport layer, and the second compound is in the second hole transport layer.
 3. The organic light-emitting diode of claim 2, wherein the second compound is in the emission layer.
 4. An organic light-emitting diode comprising: a substrate; a first electrode on the substrate; a second electrode disposed opposite to the first electrode; an emission layer disposed between the first electrode and the second electrode; a hole migration region disposed between the first electrode and the emission layer, the hole migration region comprises a hole transport layer; and an electron migration region disposed between the emission layer and the second electrode, wherein the hole migration region comprises a first compound, the first compound being in the hole transport layer and the emission layer and the hole migration region comprises a second compound, wherein the first compound comprises compound 1-8, and the second compound comprises compound 2-10:


5. An organic light-emitting diode comprising: a substrate; a first electrode on the substrate; a second electrode disposed opposite to the first electrode; an emission layer disposed between the first electrode and the second electrode; a hole migration region disposed between the first electrode and the emission layer; and an electron migration region disposed between the emission layer and the second electrode, wherein the hole migration region comprises a first compound represented by Formula 1-8 and at least one of the hole migration region and the emission layer comprises a second compound represented by Formula 2-1 or Formula 2-2:


6. An organic light-emitting diode comprising: a substrate; a first electrode on the substrate; a second electrode disposed opposite to the first electrode; an emission layer disposed between the first electrode and the second electrode; a hole migration region disposed between the first electrode and the emission layer; and an electron migration region disposed between the emission layer and the second electrode, wherein the hole migration region comprises a first compound represented by Formula 1-17 or Formula 1-19 and at least one of the hole migration region and the emission layer comprises a second compound represented by Formula 2-7, Formula 2-10, or Formula 2-19:


7. The organic light-emitting diode of claim 6, wherein the hole migration region comprises i) a first hole transport layer, and ii) a second hole transport layer disposed between the first hole transport layer and the emission layer; and the first compound is in the first hole transport layer, and the second compound is in the second hole transport layer.
 8. The organic light-emitting diode of claim 7, wherein the second compound is in the emission layer. 